#include <iostream>
#include <vector>

using namespace std;
class Solution
{
public:
    int findPeakElement(vector<int>& nums)
    {
        int left = 0, right = nums.size() - 1;
        int mid = 0;
        while (left < right)
        {
            mid = left + (right - left) / 2;
            if (nums[mid] > nums[mid + 1])
                right = mid;
            else
                left = mid + 1;
        }
        return left;
    }
}; 
int main()
{
    vector<int> nums = { 1, 2, 3, 1 };
    
    Solution xz;
    int n = xz.findPeakElement(nums);
    cout << n << endl;

	return 0;
}